I intend to study the extent to which the lifespan of a multicellular organism, the small roudworm, Caenorhabditis elegans, is subject to alteration by mutation. Since a wide variety of harmful mutations having nothing to do with the normal processes of aging could shorten th lifespan, my basic method of attack will be to look for mutant organisms that live longer than normal. To isolate such mutants, I will select organisms in which certain age-related changes develop more slowly than normal, and then will examine these organisms for longer lifespan. Specifically, the wild-type C elegans becomes infertile and moves and eats more slowly as it ages. Therefore, I will look for mutants that remain fertile, move quickly, and eat quickly when they are old. If long-lived mutants can be isolated, I will investigate: Their genetics: I will ask how many mutant genes there are that can increase lifespan; by how much single mutations can increase the lifespan; how lifespan mutations interact with one another; and whether mutations to long lifespan are dominant. Their development: I will ask whether lifespan mutants develop at the same rate as the wild type during the various stages of their life cycle. Their biochemistry: I will investiate the metabolic rate, mitochondrial function, steroid levels, rates of protein and DNA turnover, and specific activity of enzymes in lifespan mutants.